maptrims

Syntax

Description

[Z_trimmed] = maptrims(Z,R,latlim,lonlim) trims
a regular data grid Z to the region specified by latlim and lonlim.
By default, the output grid Z_trimmed has the same
sample size as the input. R can be a geographic
raster reference object, a referencing vector, or a referencing matrix.
If R is a geographic raster reference object, its RasterSize property
must be consistent with size(Z) and its RasterInterpretation must
be 'cells'.

If R is a referencing vector, it must be
a 1-by-3 vector with elements:

[cells/degree northern_latitude_limit western_longitude_limit]

If R is
a referencing matrix, it must be 3-by-2 and transform raster row and
column indices to/from geographic coordinates according to:

[lon lat] = [row col 1] * R

If R is
a referencing matrix, it must define a (non-rotational, non-skewed)
relationship in which each column of the data grid falls along a meridian
and each row falls along a parallel. latlim and lonlim are
two-element vectors, defining the latitude and longitude limits, respectively.
The latlim vector has the form:

[southern_limit northern_limit]

Likewise, the lonlim vector has the form:

[western_limit eastern_limit]

When an individual value in latlim or lonlim corresponds
to a parallel or meridian that runs precisely along cell boundaries,
the output grid will extend all the way to that limit. But if a limiting
parallel or meridian cuts through a column or row of input cells,
then the limit will be adjusted inward. In other words, the requested
limits will be truncated as necessary to avoid partial cells.

[Z_trimmed] = maptrims(Z,R,latlim,lonlim,cellDensity) uses
the scalar cellDensity to reduce the size of the
output. If R is a referencing vector, then R(1) must
be evenly divisible by cellDensity. If R is
a referencing matrix, then the inverse of each element in the first
two rows (containing "deltaLat" and "deltaLon")
must be evenly divisible by cellDensity.

[Z_trimmed, R_trimmed] = maptrims(...) returns
a referencing vector, matrix, or object for the trimmed data grid.
If R is a referencing vector, then R_trimmed is
a referencing vector. If R is a referencing matrix,
then R_trimmed is a referencing matrix. If R is
a geographic raster reference object, then R_trimmed is
either a geographic raster reference object (when Z_trimmed is
non-empty) or [] (when Z_trimmed is
empty).